spotless watermeal, rootless duckweed wolffia arrhiza and duckweed lemna turionifera

spotless watermeal rootless duckweed stagnant freshwater pond lemna wolffia alga algae aquatic plant plants araceae common duckweeds floating flora fresh green background growth invasive species lake leaf leaves lemnaceae natural nature petal pistia pool seaweed stratiotes surface swamp tiny top view water cabbage lettuce